SOLDIERTOWN TOWNSHIP, Maine — An organization funded by a millionaire philanthropist seeks a permit to build a $5 million outdoor education facility near Baxter State Park and the national monument, with hopes of opening it next fall.

If permitted by the state Department of Environmental Protection, Maine Waterside Trails will be built on the East Branch of the Penobscot River off Route 11. It will be the first large-scale investment near the Katahdin Woods and Waters National Monument since President Obama created the national park in August.

Millionaire philanthropist Gilbert Butler, founder of the Butler Conservation Fund, “fell in love” with the Katahdin region when he started kayaking there five years ago, Carl Carlson, the foundation’s director of conservation infrastructure projects in Great Neck, New York, said Friday.

An environmental philanthropist since 1988, Butler created the foundation to preserve nature, often in places the avid outdoorsman had visited, after a highly successful career developing alternative investment vehicles for pension funds, endowments, and other institutions. Butler’s foundation had $134 million in assets as of the end of 2015, according to the fund’s biography.

“He told me once that [the river] is like when Thoreau was up there. It is just this wilderness, and you don’t get any experience like it anywhere else because of development,” Carlson said.

Catering for the moment only to organized trips, Waterside Trails will expose as many as 3,500 students in grades 4-12 annually to hiking, mountain bike trail riding, snowshoeing and cross-country skiing, plus an outdoors curriculum, Carlson said. The Waterside Trails proposal calls for the construction of a 3,000-square-foot administrative office and storage facility on the river’s east bank in Soldiertown, a Penobscot County township southwest of Stacyville and north of Millinocket.

The proposal also calls for construction of about eight miles of trails through some of the 5,000 acres of foundation-owned land in the area, including one trail that will run to within 800 feet of monument lands, said Matthew Polstein, a local businessman and former Millinocket Town Council member who oversees the Butler Conservation Fund’s educational programming in Penobscot County.

The Maine Department of Environmental Protection will review the organization’s proposal after foundation members hold a public informational meeting on it at 6 p.m. Thursday, Feb. 2, at Katahdin Higher Education Center in East Millinocket. The informational meeting is a required step before submitting a building plan. A permit application to DEP to build the trails and buildings is expected to follow in 90 days.

The proposal will allow the foundation to shift some educational activities from a smaller base built on the Passadumkeag River in Passadumkeag that has been operating for a few years. That facility will remain open, Polstein said.

“Our goal is to eventually open this to the public as well so that anybody interested can join us. For now it is just for students,” Carlson said.

The students come from schools in the area between Newport and Houlton during the school year to experience outdoor activities they might not otherwise see. The idea is to enrich them with exposure to nature, Polstein said. Their visits usually last a day.

Butler is traveling in South America, Carlson said, and could not be reached for comment.

Butler began doing philanthropic work after making his fortune with Butler Capital Corporation, which managed investments on behalf of pension funds for some Fortune 500 companies, among other investors, according to his biography.

This project will draw people to the Katahdin region, which has lost much of its population and local economy with the closure of two paper mills. That possibility heartens Richard Schmidt III, chairman of Patten’s Board of Selectmen and a monument supporter.

“This is exactly what we would hope and expect to see in light of the monument designation,” Schmidt said. “I believe that this is a sign of things to come.”